The present invention relates to an art of conversion for converting a television cinema signal using interlaced scanning system (referred to as an interlaced scan telecine signal, hereinafter) into a television cinema signal using sequential scanning system (referred to as a progressively scanned telecine signal), for example, an art for converting an interlaced scan telecine signal converted from a picture like an movie film of which the number of frames per second is smaller than the field frequency like into a progressively scanned telecine signal.
Conventionally, a 2-3 pull-down system has been used as an art for converting a picture obtained from a movie film and the like into a television signal.
The 2-3 pull-down system is an art for converting a picture like a movie film of which the number of frames per second is smaller than field frequency into an interlaced signal.
For example, a movie film comprises twenty-four frames per second. Conversely, a present interlaced signal comprises sixty frames per second. Consequently, simply converting a movie film picture into an interlaced signal causes a problem.
Therefore, the above-mentioned 2-3 pull-down system is used in order to convert a movie film picture into an interlaced signal. The 2-3 pull-down system is explained as follows, referring to FIG. 11. In the 2-3 pull-down system, the first frame is converted into two fields of the interlaced signal and the following second frame is converted into three fields of the interlaced signal. This sequence is repeated at intervals of 1/12 second. That is, converting two frames of the movie film into five fields of the interlaced signal is considered as one sequence for processing.
For example, in consecutive frames A, B, C, D . . . of the film in FIG. 11, picture information A on the first frame A is converted into an odd scanning line signal A1 of the picture information A to be converted into the first interlaced field I1 and an even scanning line signal of the picture information A2 to be converted into the second interlaced field I2.
Next, picture information B on the second frame B is converted into an odd scanning line signal of the picture information B1 to be converted into the third interlaced field I3, an even scanning line signal of the picture information B2 to be converted into the fourth interlaced field I4 and an odd scanning line signal of the picture information B3 to be converted into the fifth interlaced field I5.
In this manner, the following frames C, D . . . are converted.
Wide clear vision broadcasting that started in Japan on July, 1995 uses a progressively scanned signal as a signal source.
Therefore, a camera and sequential scanning VTR corresponding to sequential scanning system used for obtaining a progressively scanned signal are required. A telecine unit is also required in order to obtain a progressively scanned telecine signal from a movie film and the like.
However, a telecine unit using a sequential scanning camera is more expensive than a conventional interlaced scan telecine unit and the like, therefore no broadcasting station adopts the telecine unit with a sequential scanning camera.